Bingo machines are gambling devices. They have a 10c coin acceptor, but they had what we called a "notes" feature, where the guy behind the counter accepted your "notes" and clocked up the games on the counter. They are a SIMPLE game to master, and, they are a lot of fun. The idea is like "connect 4" - line your squares up with the corresponding numbers. "Buy" features such as the ability to move 4 numbers around, or "reveal" a new set of numbers.. Hard to explain, but easy to demonstrate. There's not much skill involved. It is the player against the features of the game - put more money into the machine and the ability to manipulate the playfield to increase your odds occurs. Tilt is set on the game, and you can literally lose money JUST by tilting the machine. No skill - but VERY addictive.
You are playing against the machine, for money - thats why they were called "money machines" by operators and players. When I was a child growing up, I saw walls full of them.
Nowadays - they are VERY desirable to own and play. Fixing them is a huge challenge. As far as artwork goes, these were the best art packages from any era.